If F1 + F2 = 0, They must be equal in magnitude and opposite in direction. They cannot have different magnitudes(lengths).
If F1 and F2 are unequal, a third force may be added to give a sum of zero. However, the third force must be equal to the sum of the first two and opposite in direction:
F1+F2 + F3 = 0, F3 = -(F1+F2) = -F1-F2.
Remember, we are talking about VECTOR sums.
Can you find two vectors with different lengths that have a vector sum of zero? What length restrictions are required for three vectors to have a vector sum zero? Explain.
1 answer